Mitsubishi Montero Sport (2004+). Manual - part 204

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-229

STEP 11. Retest the system.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function 

− OBD-II Drive Cycle − Procedure 6 − 

Other Monitor 

P.13A-4

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0135 set?

YES : Replace the PCM. Then go to Step 12.
NO :  It can be assumed that this malfunction is intermittent. 

Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

P.00-7

.

STEP 12. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function 

− OBD-II Drive Cycle − Procedure 6 − 

Other Monitor 

P.13A-4

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0135 set?

YES : Repeat the troubleshooting.
NO :  The procedure is complete.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-230

DTC P0136: Heated Oxygen Sensor Circuit (bank 1 sensor 2)

AK000458

Right Bank Heated Oxygen Sensor (rear) Circuit

1 2
3 4

BLA

CK

BLA

CK

BLA

CK

BLA

CK

WHITE

BLA

CK

BLA

CK

BLA

CK

WHITE

WHITE

BLA

CK-RED

BLA

CK-RED

POWERTRAIN CONTROL MODULE (PCM)

1

10

15

2

11

3

12

4

13 14

5

16

6

17

7

18

8

19

9

20

E-44

E-47
MU802665

74

57

20

2

11

20

12

4

5

13

4

2

3

1

C-91

C-90

FROM MFI RELAY

TO PCM

RIGHT BANK HEATED
OXYGEN SENSOR (REAR)

1

10

15

2

11

3

12

4

13 14

5

16

6

17

7

18

8

19

9

20

E-45

E-45

47

41

42 43

48 49 50 51 52 53 54 55 56 57

46

45

44

58

59

60 61 62 63

64 65 66

C-90
(MU803781)

1

10

2 3 4 5 6 7 8 9

11

12 13 14 15 16 17 18 19 20 21 22

23 24 25 26 27 28 29 30 31 32 33

C-71

71

76

77

72 73 74

75

79 80

78

81

87 88

89

91

90

92

97

98

82

93

83

94

84 85

95

86

96

C-91
(MU803782)

6

10

2

7

8

3 4 5

9

11 12 13

1

C-79
MU801553

JOINT
CONNECTOR (4)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-231

.

CIRCUIT OPERATION

• A voltage corresponding to the oxygen concen-

tration in the exhaust gas is sent to the PCM (ter-
minal No. 74) from the output terminal (terminal 
No. 4) of the right bank heated oxygen sensor 
(rear).

• Terminal No. 2 of the right bank heated oxygen 

sensor (rear) is grounded with PCM (terminal No. 
57).

.

TECHNICAL DESCRIPTION

• The output signal of the right bank heated oxygen 

sensor (front) is compensated by the output sig-
nal of the right bank heated oxygen sensor (rear).

• The PCM checks for an open circuit in the right 

bank heated oxygen sensor (rear) output line.

.

AK103912AB

CONNECTOR: C-71

C-71

AK103738AE

CONNECTORS: C-90, C-91

PCM

C-91(GR)

C-90(GR)

AK200018 AC

CONNECTOR: E-45

E-45(B)

AK103911AC

CONNECTOR: C-79

C-79

AK200018 AB

CONNECTOR: E-44

E-44

AK200491

E-47(GR)

AB

CONNECTOR: E-47

RIGHT BANK
HEATED OXYGEN
SENSOR (REAR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-232

DESCRIPTIONS OF MONITOR METHODS
Right bank heated oxygen sensor (rear) circuit is 

switched to 5 volts intentionally when oxygen 
sensor output is low, and detects the malfunction 
if the output voltage changes to equal or greater 
than 4.5 volts. The above procedure is repeated 
when oxygen sensor is inactive.

.

MONITOR EXECUTION
Continuous

.

MONITOR EXECUTION CONDITIONS (Other 
monitor and Sensor)

Other Monitor (There is no temporary DTC stored 

in memory for the item monitored below)

• Heated oxygen sensor heater (front) monitor

• Heated oxygen sensor heater (rear) monitor

• Air/fuel ratio feedback monitor

Sensor (The sensor below is determined to be 

normal)

• Volume airflow sensor

• Engine coolant temperature sensor

• Intake air temperature sensor

• Barometric pressure sensor

.